I like scrapers about as much as I like spammers so anything I can do to thwart their efforts is a win in my book! 
Update: Actually, after some thought, I'm wondering if this plugin is such a good idea after all. At least some scraped sites no doubt will be hosted on sites designated by the various search engines as "bad neighborhoods". Is having incoming links from these areas to your sites really a good thing?
How do you guys deal with scrapers?
Update: I've disabled the RSS Footer plugin for now. Instead, I'm displaying a Creative Commons license on blog posts and I've added the license to the feed also. More here.
The Make scrapers work for your blog article by Aral Balkan, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-Noncommercial 2.0 UK: England License.
Hey Aral, though I can understand your thoughts, I would not worry to much about that, if anything, these links will help search engines to acknowledge the right version of the article.
One can also include a lot of links to your other stories (e.g. as we discussed in xxx), such that if they just drop it in as a whole you may get traffic coming in via your copies.
“Is having incoming links from these areas to your sites really a good thing?”
It won’t be a bad thing for your site. If Google penalises the linked site, then SEOers could attack well-respected sites by linking to it from dubious sources. Now if _you_ link to the bad neighbourhood, that would be something penalisable.
Whether there’s any good - I think Joost above nails it. If a bad neighbourhood links to your post, that must mean your post existed first, therefore should have a higher ‘original author’ score.
I write a blog that nobody cares about. That’s how I deal with scrapers!